You must read the disclaimer before downloading.
It's completely free, open source and easy to use.Using a web camera, you can configure a particular spot in which motion is detected to trigger a mouse click or a keystroke. As no particular features or shapes are detected, events can be fired using almost any part of the body or object moving in front of the camera. Currently, up to two virtual switches can be emulated.
Before running sViacam make sure that the web camera is already installed and works properly.
Cross-platform: Switch Viacam currently runs on Windows XP/Vista/7 and GNU/Linux
License: Switch Viacam is free software released under the terms of the GNU General Public License version 3.
Contact: cesar at crea-si dot com